According to Kadokawa, an OVA of R-15 will be bundled with the tenth volume of the novel.

R-15 is about a boy, Taketo Akutagawa, who attends a school for geniuses: Inspiration Academy Private High School. Taketo is a genius novelist and writes erotica. Despite negative perceptions many people have of him, he aims to be at the top of his class and be recognized as the world's greatest writer.

A series of comedic shorts featuring chibi versions of the characters of the main show.

Afraid that his life may end at any moment, Otto Suwen begins writing a diary documenting all of his experiences. Now part of Subaru Natsuki's eccentric band of colorful characters, the apprehensive merchant is certain that new dangers lie ahead in their mission at Sanctuary. But amid the rising tensions, there are still moments of respite and reflection, ripe with opportunities to make vivid memories.